Typewriting machine



Nov. 20, 1928. 1,691,922

w. A. DOBSON TYPEWRITING MACHINE Filed Oct. 8, 1925 W4 AM f Affor /z the platen to overthrow. As the rearward 7 limit of movement of the slide 13 is reached,

the spring 27 becomes disengaged from its contact with the abutment'29, and, at this point, an overthrow-lock 30, integral withthe pawl 15, and having an angular upper surface 31, engages with theangular surface 32 of the abutment 29, whereby rotation of the platen and ratchet will be effectively arrested at the end of the line-space stroke.

In order to vary the-line-spacing of the.

platen, I provide a regulator which may preferably include an arm 33, pivoted upon the platen-shaft 20, and having adjacent its extremity a table 34, which supports the pawl 15, limiting its down'ward movementabout the pivot 16. A suitable finger-piece 35 may be operated to adjust the arm. 33, said fingerpiece extending through an arcuate slot 36 in the end plate 21; A yieldable detent 37 engages anoppositely-disposed arm 38 of the regulator to hold. it in adjusted positions for either single or double line-spacing. When the table 34 is in its lowest position, as shown in Figure 2, the platen will be double spaced by actuation of the lever 10; and, when the table 34 is in its upper position, as shown in Figures 5 and 6, single spacing may be obtained.

A roller-detent 39 normally engages the teethof the ratchet 18 to insure proper linespaced position of the platen, said roller-detent being supported upon a resilient arm 40,

adjacent the detent 37 A lever 41, having .a cam-surface 42, engages the pivotal support of the roller-detent 39, as best shown in Figures 2 and 5, whereby the detent may be released from engagement with the ratchetwheel 18, to facilitate fractional line-spacing. A suitable finger-gripping portion 43 is provided on the upper extremity of the lever 41,

and may be drawn forwardly'to the position shown in dot-and-dash lines in the drawings.

In theevent that the operator should release the detent 39 from engagement with the ratchet-wheel, subsequent operation of the line-space lever 10 will automatically return the detent 39 to its normal position by virtue of the fact that the lever 41 is disposed in the path of movement of the line-space slide 13; This feature will be more clearly understood froma study of Figure 5 of the drawings, wherein the interference between the line-space slide 13 and the lever 41 is clearly illustrated. Y

It will be seen that to solve the problem of compactness of the line-space lever with its pawl and to secure efliciency,: the lever has a long arm which extends forwardly and backwardly alongside of the end of thecarriage and close thereto, with a short arm extending in from said lever through the end of the carriageythis short arm 14 swinging backwardly when the long arm-lever or the line-space lever returns the carriage. This backward swing of the lever 14 is communicated to the line-spacing pawl '17 by an improved train, since it would be impracticable to mount said pawl directly upon the arm 14 without sacrificing some of the work that the pawl 17 must do. In order. to secure efiiciency and compactness it is mounted upon a slide 13 which is guided by the end frame'21 of the carriage, and which lies against the inner surface of the end plate 21 of the carriage, and .is pivotally connected at its rear end to the arm 14, and is guided atits front end by its stud-screw 22 in the slot 24 in the end of the-carriage. The pawl 17 is mounted on this slide between the slide and line-space wheel 18. The line-space wheel 18 ispocketed just making the machine any larger, said stop 29 overhangs the slide 13 and juts into the path of the stop-tooth 30 on the pawl, which liesclose alongside the slide 13, see Figure 1. Compactness is further maintained by arranging the line-space regulator 33 in the form of a lever loosely pivoted for compactness on a boss on the platen-end, through which extends the platen-axle 20, said regulator 33 pocketed under the slide 13, so as not to add anything whatsoever to the length of the carriage, and having a finger-piece 35 projecting'out through a slot 36 in the end of the carriage-and falling shortof the lever 11, so as not to increase the exterior length of the carriage this line-space lever33 formed with a lip 34 projecting under the pawl 30, and also below the slide 13. Thus the parts 13 and 33 lie one above another in-the same plane and within the shell or pocket 21 which constitutes the end of the carriage. Also under the slide 13, and therefore not occupying any room and not extending the carriage,

is the detent-release lever 41,-43, which is also provided on the boss onthe platen-frame end. If all of the parts 13, 15, 33, 34 and 41, etc., were to be removed from the machine, the carriage could be no shorter. While the lever 11 lies outside of the carriage-frame, still the whole lengthof the carriage, including said'lever, is much shorter than is customary. I

The use of a very wide sheetof paper is permitted, extending, intact, far enough to almost touch theinner edge of this end .21

of the platen-frame, Without fouling the mechanism. Moreover. all the ,moving parts,

i the pawl downwardly.

i'ied positively into mesh with the teeth of.

theratchet-wheel at the operation of the line space lever 11. Spring 27 normally is under pressure at its free eiid,being fastened at its rear end to the slide. 1 The free front end of the spring 27 normally stands under the lug 29, and is pressed down thereby, so as to force Hence, at the operation of the lever 11, the slide 13 and the spring 27 and the pawl 15 move rearwai'dly substantially as a unit, and the spring forces the pawl to enter a notch in the toothed wheel The position of 18, and to rotate'the wheel. the spring at the end of its platen-rotating stroke is seen at Figure 6. The bulge in the spring 27 is to enable it to be'carried down by the lug'29, which is at a high elevation. The bulge simply carries the spring up far enough to reach said lug 29. It makes little differ ence whether the spring 27 is or is not pressed down at the Figure 6 position, because the work of rotating the platen has been finished.

This invention constitutes a line-spacing unit manufactured separately 'from the remainder of the carriage. 33, 10, 41, 37, 25, 34,35, etc., are assembled in final positions upon the plate 21, thus .forming a complete manufactured unit. can then be placed in position upon the carriage, the hole in the plate sliding'upon the end 20 of the platen-axle, and the hole at the left-hand end of the plate 21 fitting upon the cylindrical rear bar which forms a part of the carriage-frame, and is seen at Figures 1 and 2. This plate 21 may be detached from the machine and' examined and cleaned and repaired as a unit, and then replaced as a unit upon the carriage. Portable typewriters are dropped on the floor, are thrown about by the baggageman, they are roughly handled by children and by amateur operators, and they are constantly in need of repair and replace ment of parts. things into the form of a unit is an element that is of substantial importance in making a portable typewriting machine business successful.

The requirements of a portable machine are compactness, cheapness, lightness, acessibiL ity, simplicity and durability." The dished part of the carriage-frame forms a pockethousing for a compactly arranged line-space ing mechanism. The handle swings in a plane close above the top of the side-plate. All form one unit. It will be noted that the whole pawl-actuating mechanism is compactly and accessibly arranged at the top portion of the side-plate. This also gives, according to another feature, good opportunity forcooperation between the line-space lever and a detent-release lever which is usually located All parts 14, 13, 15,

This unit The combining of all these at the rear,-with suitable shape of the elements; the operating stroke of the line-spam ing slide-bar will directly throw the detentrelease lever backward to restore the detent P to operative position upon the line-space Wheel, in case the operator neglected to individually restore the detent-roller after positioning a work-sheet.

The top arrangement of the pawl-actuating mechanisin'also gives opportunity for compactly housing tllBflbOVG-IHGHCIOIIGC]. variable line-spacing member (without additional space), the handle of which maybe easily locatedand conveniently operated in upward and downward movement.

improvements maybe used without others..-

Having thus describedemy invention, I claim:

1. In a typewriting machine, the combi- Y The pawl-actuating mechanism is compact,

nation with a rotatable platen, of a line-space wheel rotatable therewith, means to actuate vent overthrow, and means to disengage the detent, said disengaging'means being autotlle line-space wheel to line-space the platen, a detent engaging the line-space wheel'to prematicallyreleasable upon actuation of the line-spacing means.

2. In a typewriting machine, the combina- 'tion witha rotatable platen, of a line-space wheel rotatable'therewith, means to actuate the line-space Wheel to line-space the platen,

a detent engaging theline-space wheel to prevent overthrow, and means to disengage the detent, said disengaging means being dlS posed in the path of movement'of and oper-' able by theline-space actuating means.

3. In a typewriting machine, the combination with a rotatable platen, of a line-space wheel rotatable therewith, a carriage-return lever, a driving connection between theicarriage-return lever and the line-space wheel','. means normally engaging the line-space wheel to prevent overthrow of the platen,

and means todisengage the last-mentioned means, said disengagingmeans being releasable by actuation of the carriage-return lever.

4. In a typewriting machine, the combination with a rotatable platen, of a ratchet wheel rotatable therewith, a line-spacing lever, adriving connection between the linespacing lever and the ratchet-wheel, a yieldable detent engaging the ratchet-wheel to prevent overthrow of the platen, and detent-' releasing means disposed in the path of movement of the-line-spacing lever.

5. In a typewriting machine, the combinatin with a rotatable platen and acarriage therefor, of a line-space ratchet rotatable with the platen, a line-spacelever pivoted on the carriage, a slide movable transversely of the platen-axisand positively connected to theline-space lever, apawl .pivoted on the slide to engage and ride upwardly on the rotating ratchet, and means mounted on the carriage above the slide .and co-operative with the upward movement of the pawl to effect a Wedging movement of the pawl to prevent overthrow of the platen.

6. In a-typewriting machine, the combination with a rotatable platen and a carriage therefor, of a line-space ratchet rotatable with the platen, a-line-space lever pivoted on the carriage, means-includlng a pawl for transmitting motion fromthe line-space leverto' the ratchet, yieldable means for pressing the, pawl into engagement with the ratchet, and an abutmentengaging the yieldable means and flexing the same against the pawl at the beginning of theline-space stroke.

7; In a-type-writing machine, the combination with a rotatable platen and a carriage the platen, a line-space lever pivoted on the carriage, a'zslide movable transversely of the platen-axis'and operable by the line-space lever, a pawl pivoted on the slide toengage the V ratchet, astop to limit the. movement of said pawl, and a spring carried by the slide and engaging the pawl -to press the pawlagainst the ratchet, said spring being actuated by the stop toexert a greater pressure on the pawl at the beginning of the line-space stroke.

9. In a typewriting machine, the combination with a rotatable platenand a carriage therefor, of a line-space ratchet rotatable with the platen, a line-space lever pivoted on the carriage, a slide movable transversely of the platen-axis and operable by the line-space lever,-a pawl pivotedon the slide to engage the ratchet, a stopto limit the movement of said pawl, a spring carried by the slide and engaging the pawl-topress the pawl against the ratchet, said spring'being actuated by the stop to exert a greater pressure on the pawl at the beginning of the line-space strokea detent engaging the ratchet to justify the platen,and=means-including a eam for dis engaging the detent fromxthe ratchet, said means being releasable by operation of the line-space lever.

10. In a typewriting machine, the combination withcaplatenand a platen-carriage, of

a line-space ratchet rotatable with the platen, a carriage-return lever, a rearwardly-movable slide mounted on the carriage and operable by the carriage-return lever, a pawl piv oted on the slide, a spring carried by the slide and pressing thepawl against the ratchet, and means to increase the pressure of the spring on the pawl near the beginning of the line-space stroke and finally to arrest the movement of the. pawl at the end of thestroke. 11. In a typewriting'machine, the combinationwith a revoluble platen and a ratchet- V wheel rotatable therewith, of means for actuating the ratchet-Wheelto line-space the platen, af detent normally engaging the ratchet-wheelto prevent overthrow, and a cam-lever for manually disengaging thede tent to allow a free rotation of the platen, the

arrangement being such that whenthe detent is disengaged, actuation of the line-space means will operate the cam-lever to restore said detent to engaging position.

12. In a typewriting machine havinga rev- 'oluble platen and a carriage .therefor,the

combination with a ratchet-wheel rotatable with said'platen, ofa line-spacelever pivoted to one end of said carriage, means, including a slide and a pawl pivotedthereto, operated by the line-space lever .to actuate the ratchetwheel, a leaf-spring mounted on said slide and bearing down upon the pawl for urging the latter against'the ratchet wheel, and an abutment mounted onthe carriage above the pawl both for pressing the leaf-pring against the pawl at the beginning of. the line-space movement and for limiting the travel of the pawl at the end of said movement.

13. Ina portable typewriting machine, the

combination of a carriage,-a platen :mounted thereon and having a line-space wheel, said carriage having an end, and the following train of instrumentalities all mounted 'on said end to form therewith a manufacturing unit, viz., valine-space handle in the form of a bell-crank, a spring-returned slide connected to the short arm of said bell-crank, a

pawl driven by said slide, a spring-pressed detent to engage the line-space wheel, a releasing device for said detent, and a linespace regulator pivoted around the platenaxle between said carriage end and the line space wheel. v

14. A machine constructed according to claim 13, in which the slide lies alongside of the inner face of the carriage end, and is pivoted at its rear end to the short arm of the bell-crank, and is supported at its forward end in a slot in the end of the carriage,the

pawl being pivoted upon-the slide, a lug upon the carriage frame end engaging the pawl tooth to lock theplaten again-st overthrow, and a line-space regulating lever having a lip on which the pawl normally rests out of engage ment with the line-space wheel, said linespace regulating lever having a handle pro- 15. A machine constructed according to claim 13, in which the slide lies alongside of the inner face of the carriage end, and is pivoted at its rear end to the short arm of the bell-crank, and is supported at its forward end in a slot in the end of the carriage, the pawl being pivoted upon the slide, a lug upon the carriage frame end engaging the pawl tooth to lock the platen against overthrow, a line-space regulating lever having a lip on which the pawl normally rests out of engagement with the line-space wheel, said linespace regulating lever having a handle projecting through the platen frame end, said regulating lever occupying the space directly under the slide for compactness, and a platen-detent release also lying in the space under the slide, and having a shoulder to engage the platen-detent to release it.

16. A machine constructed according to claim 13, in which the spring normally is pressed down by a lug fixed upon the platen frame end to press upon the pawl to insure the engagement of the latter with a notch in the line space Wheel at the operation of the line-space handle; v V

i WILLIAM A. DOBSON. 

